1. Field of the Invention
The present invention relates to a recording tape cartridge. The recording tape cartridge accommodates a single reel around which a recording tape, such as a magnetic tape, primarily used as a recording/playback medium for a computer or the like.
2. Description of the Related Art
A conventional magnetic tape cartridge is known, being constructed such that a magnetic tape used as a data recording/playback medium for a computer or the like is wound on a single reel, and the reel is accommodated in an accommodating case. A leader member, such as a leader pin, a leader tape, or a leader block, is provided to the end of the magnetic tape. The leader member is pulled out from an opening of the magnetic tape cartridge by using pull-out means provided in a drive device, and the magnetic tape fixed to the leader member is wound around a take-up reel in the drive device.
A reel gear is formed annularly in the center of the reel lower surface appearing from an opening formed on a lower surface of the magnetic tape cartridge, a drive gear provided on a rotation shaft in the drive device is engaged with the reel gear, and the reel is thereby rotationally driven. Therefore, data can be recorded on the magnetic tape, or data recorded on the magnetic tape can be played back in such a manner that the reel of the magnetic tape cartridge and the take-up reel of the drive device are rotated in synchronization.
Magnetic tape cartridges of the above-described type are characterized in that the accommodating space for preservation can be small, and a large amount of information can be recorded. As shown in FIG. 8, when a leader pin 70 is provided at an end of a magnetic tape T, which is wound around a reel 72, an opening 68 is formed on a sidewall 64 of an accommodating case 62 formed parallel to the direction of insertion to the drive device (direction of an arrow P). In this case, a door 66 slidably moves in the same direction as the direction of insertion to thereby open and close the opening 68.
This type of door 66 is assembled in the case 62 by a coil spring 67 being placed on a shaft 65 which projects at the rear end portion of the door 66, and the rear end portion of the coil spring 67 being anchored on an anchor portion 69 provided at the case 62. In this way, the door 66 is always urged in the direction of closing the opening 68. Due to the door 66 sliding in the direction opposite to the direction of arrow P as the magnetic tape cartridge is loaded into a drive device, the door 66 opens the opening 68 as shown in Japanese Patent Application Laid-Open (JP-A) No. 2001-148179 and Japanese Patent Application Laid-Open (JP-A) No. 2000-76821, the disclosures of which are incorporated by reference herein.
When the door 66 is assembled into the case 62, the door 66 must be assembled while anchoring the rear end portion of the coil spring 67 on the anchor portion 69 and pressing the rear end portion so that it does not come off of the anchor portion 69. Thus, this assembly operation tends to become troublesome, and the assemblability is not always good.